CROMI is actually pretty nice compared to stock, very solid and reliable on the beta 4 version (latest). My TF doesn't get as hot either compared to stock but YMMV.
The CM12 release is pretty solid as well although i haven't tested battery life, just games and basic browsing. The reason i don't use it over CROMI is due to the fact that it doesn't have any keyboard battery life indicator/gui.
This is a dealbreaker for me.
As far as the connection problems... if you've had previous problems with the keyboard connection then they will be present on either of these 2 roms.
I have one of the newer keyboard but i still suffer from random connectivity issues but they're not often enough for me to get annoyed.
